Abstract: The present invention comprises of a digital image processing method which simultaneously enhances color saturation and sharpness on a pixel-by-pixel basis directly in RGB color space, the most popular color space used to represent digital color images, and does not cause color hue shifts. The method comprises the steps of: developing a surround function to analyze the local brightness uniformity in a digital image; generating an intermediate image using the brightness uniformity; calculating enhancement values with a gain function in each of the RGB channels for each pixel; and adding the enhancement values to the respective RGB channels for each pixel to produce an adjusted digital color image with enhanced color saturation and sharpness.

Abstract: The present invention relates to a method for enhancing images of non-uniform brightness. In the invention, a surround function is developed to analyze relationship of individual pixel brightness to that of surrounding pixels in an image. This brightness information is then used to set a gain function to decide the required adjustments on the values of RGB (red, green and blue) color channels of each pixel. The final value of a pixel is the sum of the adjusted values of R, G and B channels. The present method is capable of imitating human vision and adaptively adjusting brightness in every region of an image while preserving the color consistency.